Biomedical subjects

Patrick Simon

Publications and source records attributed to Patrick Simon.

3 recordsLinked to original sources

PubMed2006

Thoracolumbar fractures surgically treated by "in situ contouring".

This is a retrospective study on a series of 70 patients with thoracolumbar fractures (TL), surgically treated by the in situ bending technique (ISB). Its purpose is to show the performances and limits of the ISB technique for the early correction of post-traumatic spine deformities as well as to estimate the overall outcome in this series and to discuss the indications for anterior grafting. Although the management of limbs fractures is a cleared issue today, spine fractures management is still a matter of debate. Surgical treatment progresses fast, while indications, the fixation techniques, fracture reduction options, and associated grafting are still blurry. Seventy patients with TL fractures, mean age 40.3 years (20-80) were treated by posterior fusion with a standard construct and deformity reduction by means of the ISB technique. Mean follow-up was 30.7 months (12-78). Pre- and post-operative deformity was evaluated and the relative deformity as defined by Farcy's sagittal index (SIF) was analyzed. Thirty-eight patients underwent anterior interbody grafting. The pre-operative SIF decreased from 16.98 to 1.62 degrees (15.36 degrees decrease). Eighty percent of patients were normo- or hyper-corrected. The loss of correction during the follow-up occurred within the disc (SIF: -2.24 degrees , vertebral kyphosis 0.94 degrees , p<0.001), and was lower in patients who underwent secondary anterior grafting (-5.21 degrees vs.-1.18 degrees , p=0.002). Clinical outcome is good (Oswestry=29.75) and seems to be better in cases of double approach (20.71 vs. 37.,4, p=0.001). Sepsis occurred in ten cases, and two patients experienced construct dismounting. One patient had a retroperitoneal hematoma that required embolization. Seventy-one percent of operated patients went back to their previous work after surgery. Spine fractures deserve an efficient treatment. The ISB technique improves post traumatic kyphosis. This results is maintained at long term if the posterior fusion is associated with anterior grafting in cases where the correction within the disc exceeds 50% of the total correction.

Adult↗

PubMed2002

Perforations of cortical bone allografts improve their incorporation.

The incorporation of perforated cortical bone allografts was compared with non-perforated allografts. A 5-cm circumferential defect in the middiaphysis at the tibia was created in adult sheep. A frozen tibial allograft was implanted and fixed with a locked nail for 6 months. There was no postoperative immobilization. Group I consisted of eight sheep with non-perforated allografts, whereas Group II was comprised of 10 sheep with perforated allografts. Union was evaluated radiographically, whereas the central part of the allograft had a densitometric evaluation. Creeping substitution was assessed on microradiographs from cross-sections of the central 3 cm of graft by measurement of porosity and percentage of new and old bone area within the confines of the graft. The width of periosteal and endosteal callus also was determined. There was no statistical difference between both groups for the union score and bone density. However, the cortical bone graft porosity and the amount of new bone within the cortical bone differed significantly between the perforated allografts and the non-perforated ones. Periosteal callus was similar in both groups, whereas endosteal callus was significantly more wide and extended in the perforated allografts. Perforation of a cortical bone substantially improved the amount of newly formed bone by the host when compared with a non-perforated bone. The creation of channels seemed to increase the interface between living soft tissues of the host and the allografted bone with a resulting enhanced incorporation.

Animals↗

PubMedDate not supplied

[An experimental study on freudian slips].

We attempted to replicate findings of a frequently cited study by Motley. This author had used a tachistoskope to present his participants pairs of words which had a meaning after exchanging the initial letters of each word ("spoonerisms"). In accordance with the psychoanalytic theory of Freudian slips, Motley was able to show that under the impression of a sexually stimulating situation more sexual words were read; under the threat of electric shock spoonerisms appeared more often in words with reference to electricity. In our study we tried to induce spoonerisms by presentation of short written texts of erotic, aggressive and neutral content. It could be shown that after reading the erotic and the aggressive text, slips were produced more often than following the text of neutral content. In addition, significantly more slips of erotic kind occurred after reading the erotic text, whereas more aggressive slips were observed immediately after lecture of the text with aggressive content. We were therefore able to replicate Motley's findings and thus also corroborated assumptions made by Freud on the origin of slips of the tongue.

Adult↗